Error handling in HTTP calls in Vue - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of error handling in HTTP calls in Vue?

Error handling helps manage problems like network failures or server errors when fetching data, so the app can respond gracefully and inform the user.

beginner

Which Vue Composition API function is commonly used to make HTTP calls?

The onMounted lifecycle hook is often used to trigger HTTP calls when a component loads, combined with fetch or libraries like Axios.

intermediate

How do you catch errors from an HTTP call using fetch in Vue?

Use <code>try...catch</code> inside an async function to catch errors. For example:<br><pre>try {
  const response = await fetch(url);
  if (!response.ok) throw new Error('Server error');
} catch (error) {
  /* handle error */
}</pre>

beginner

What is a common way to show users that an HTTP call failed in a Vue app?

You can use a reactive variable like errorMessage to store the error text and display it in the template with a friendly message.

intermediate

Why is it important to check response.ok after a fetch call?

Because fetch only rejects on network errors, not HTTP errors. Checking response.ok lets you detect HTTP errors like 404 or 500 and handle them properly.

In Vue, which method is best to handle errors from an HTTP call?

A Reloading the page automatically

B Ignoring errors and hoping for the best

C Using try...catch inside an async function

D Using console.log only

Using try...catch inside an async function allows you to catch and handle errors properly.

What does response.ok indicate in a fetch call?

A The fetch call was never made

B The HTTP status is between 200 and 299

C The server returned a 404 error

D The network connection is lost

response.ok is true when the HTTP status code is in the 200-299 range, meaning success.

Which Vue feature helps update the UI when an error occurs during an HTTP call?

A Reactive variables (refs or reactive)

B Static HTML elements

C Global CSS styles

D Browser alerts only

Reactive variables update the UI automatically when their values change, perfect for showing errors.

What is a good user-friendly way to show an HTTP error in Vue?

A Display a clear error message in the component

B Crash the app silently

C Show a blank screen

D Log the error only in the console

Showing a clear error message helps users understand what went wrong.

Which lifecycle hook is commonly used to start HTTP calls in Vue Composition API?

A beforeCreate

B destroyed

C created

D onMounted

onMounted runs after the component is added to the page, ideal for fetching data.

Explain how you would handle errors when making an HTTP call in a Vue component using fetch.

Think about catching errors and showing messages to users.

Describe why error handling is important in HTTP calls and how Vue's reactivity helps improve user experience.

Consider user experience and app stability.